Answer:
a) Norovirus
Step-by-step explanation:
Norovirus also known as winter vomiting bug is a very contagious virus. It causes vomiting, diarrhea and stomach pain. It can spread from eating contaminated food or by person to person. Oysters and other shell fish are very common agents of norovirus outbreaks. When they are exposed to untreated human sewage they come in contact with the virus. They filter sea water via their bodies to obtain food but norovirus is able to cross their bodies and accumulates inside them. Oysters are typically at more risk of transmitting the disease because they are eaten raw. To reduce the risk of norovirus shellfish should be cooked at a temperature of 145 degrees Fahrenheit.